Whate’er my God ordains is right:His loving thought attends me;No poison can be in the cupThat my Physician sends me.My God is true; each morn anewI’ll trust His grace unending,My life to Him commending.

In Calvin's commentary on 1 Corinthians he discusses what it means to "examine yourselves" at the Lord's Supper. He describes the Papists (or Catholic) way of self-examination as self-inflicted torture and contrasts it with the true meaning. I couldn't help but blush at how much the Papists' practice sound like our own!

But now it is asked, what sort of examination, that ought to be to which Paul exhorts us. Papists make it consist in auricular confession. They order all that are to receive the Supper, to examine their life carefully and anxiously, that they may unburden all their sins in the ear of the priest. Such is their preparation! I maintain, however, that this holy examination of which Paul speaks, is widely different from torture. Those persons, after having tortured themselves with reflection for a few hours, and making the priest — such as he is — privy to their vileness, imagine that they have done their duty. It is an examination of another sort that Paul here requires — one of such a kind as may accord with the legitimate use of the sacred Supper.

You see here a method that is most easily apprehended. If you would wish to use aright the benefit afforded by Christ, bring faith and repentance. As to these two things, therefore, the trial must be made, if you would come duly prepared. Under repentance I include love; for the man who has learned to renounce himself, that he may give himself up wholly to Christ and his service, will also, without doubt, carefully maintain that unity which Christ has enjoined. At the same time, it is not a perfect faith or repentance that is required, as some, by urging beyond due bounds, a perfection that can nowhere be found, would shut out for ever from the Supper every individual of mankind. If, however, thou aspirest after the righteousness of God with the earnest desire of thy mind, and, trembled under a view of thy misery, dost wholly lean upon Christ’s grace, and rest upon it, know that thou art a worthy guest to approach the table — worthy I mean in this respect, that the Lord does not exclude thee, though in another point of view there is something in thee that is not as it ought to be. For faith, when it is but begun, makes those worthy who were unworthy.